The invention is applicable in particular to folders of offset rotary presses.
Such a device for braking a flat product is known from the document FR-A-2 793 229.
This device uses an electromagnet in order to move the brake lining from its passing position towards its braking position.
However, electromagnets are not very reliable.
Consequently, the object of the invention is to increase the reliability of the braking device, in particular when production rates are high.